When the excavator walks slowly, many people don't know how to check and find out the cause of the fault. A total of 9 causes of slow walking are summarized. This article will describe five causes of faults caused by slow walking of excavator and corresponding troubleshooting methods for reference only.
1. The valve core of the main traveling valve deflected by the excavator fails to act
If the spring in the traveling main valve becomes soft or broken, or the valve core is stuck, the oil pressure may be reduced and the traveling deviation may occur. During inspection, measure the pressure of the oil circuit of the traveling main valve, and the normal value is 30.5mpa. If the traveling main valve is damaged, it needs to be replaced or repaired. In case of traveling deviation fault, first consider whether the traveling main valve core has been damaged.
2. The traveling oil suction valve on the deflection side of the excavator is damaged
The oil suction valve is installed on the hydraulic cylinder and motor of the working device. When the hydraulic cylinder or motor is greatly impacted by the outside world, the abnormal high pressure in the hydraulic cylinder or motor can be removed, so as to protect the relevant oil pipes and cylinders from damage. If the travel oil suction valve is damaged and the spring in the valve is soft or broken, the oil pressure in the travel main valve will be reduced, resulting in insufficient driving force of the travel motor and deviation. The troubleshooting method is to repair or replace the oil suction valve.
3. The tightening degree of the track is different from left to right
If the tension of the left and right crawlers is different when the excavator is walking, it will also deviate when walking. The troubleshooting method is to add butter to the loose side to make it as tight as the other side.
4. The performance of large pump decreases
When the excavator travels in a straight line, when the plunger of the pump flow regulator of one pump is stuck at a certain position, or due to serious wear, internal leakage, and the system pressure can only reach 29.5mpa, the speed of the traveling motor will slow down, and the excavator will deviate. The troubleshooting method is to remove the hydraulic pump assembly from the excavator, replace the worn parts, repair the regulator, and replace the hydraulic oil and filter element.
5. The output pressure of the travel proportional valve on the deflection side of the excavator is too low
The proportional valve can output the corresponding control oil pressure according to the length of the control stroke of the operating handle, so that the main control valve has the corresponding movement, so as to control the speed of the working device. If the filter element of the oil filter is not changed on time, the filter element may be blocked, the bypass valve of the oil filter may be opened, and the dirty hydraulic oil directly enters the circuit of the proportional valve without filtering, resulting in the jamming of the slide valve in the valve, and the control oil cannot flow to the main rotary control valve through the rotary proportional valve on the deflection side of the excavator, resulting in travel deviation. At this time, check the pressure of the travel proportional valve. The elimination method is to clean the valve body and front oil circuit, and replace the hydraulic oil and filter element.
